For instance, in a paper making machine, water is removed from wet pulp by pressing it between a pair of opposing rollers, and such rollers consist of press felt in the form of relatively broad endless belts. The press felt is made by entangling fibers of a pad consisting of layers of woolen or synthetic fiber web with a ground fabric by needling. During the weaving process of the ground fabric, the warps are set on a warp beam and fed continuously while the weft is supplied by a cop mounted on a shuttle. Therefore, when weaving such a broad ground fabric for making press felt, the cop is required to be changed to a new one every time the shuttle has reciprocated from one lateral end to the other by a certain number of times. Further, at the same time, the weft of the old cop and the weft of the new cop must be connected with each other by welding or the like.
Conventionally, changing cops and connecting the ends of two wefts together were carried out manually. As a result, an experienced operator was required for each weaving machine, and its was difficult to reduce the cost of weaving.